What Use Is An F-call?

What use is an F-call? I've heard it expressed that working on HF using an F-call is hard graft. No-one hears you, they don't talk to you, they ignore you, nothing works, it's all too hard. I've heard F-calls tell me that they've called CQ for hours and no-one wants to play. I understand that HF is challenging, but it's not impossible. There are a number of things going on that make that a HF contact requires more effort than talking on a 2m repeater. Making contacts on HF requires that you understand what's going on, that some of the things that you're thinking are likely not true and some of your expectations are wrong. I'm not the oracle of amateur radio, that would be a sorry state of affairs, but I can share some of the things I've learnt. Finding someone to talk to on-air is the simplest way to make a contact. That is, you scan up and down the bands, nice and slowly, to find a station that's nice and loud. If they're not moving your S-meter, it's unlikely that you're going to move theirs, or even ma